Describes a classroom activity using slime, a colloid: it behaves like both a solid and liquid. Explains how slime can be produced from guar gum. An activity where students work in teams and become a slime factory is presented. (PR)

Objectives, materials needed, procedures, discussion questions, and follow-up activities are provided for five experiments. They include (1) testing for sugars; (2) comparing sugar to artificial sweeteners; (3) chewing gum scientifically; (4) soap making; and (5) making toothpaste. (JN)

Describes an atom-building activity where students construct three-dimensional models of atoms using a styrofoam ball as the nucleus and pom-poms, gum drops, minimarshmallows, or other small items of two different colors to represent protons and neutrons attached. Rings of various sizes with pom-poms attached represent electron shells and…

Presents 10 guidelines for developing performance-based assessment items. Presents a sample activity developed from the guidelines. The activity tests students ability to observe, classify, and infer, using red and blue litmus paper, a pH-range finder, vinegar, ammonia, an unknown solution, distilled water, and paper towels. (PR)